It was obviously a business decision.
CSR was a great benefit because it is a convention resort.
POR and POFQ are the resort for a family of 5 and the compact resort for the romantic or mid age set.
CBR added the pirate rooms to fill the most remote part of the resort, because the layout is more elongated of the four moderates (not counting the Cabins which are also doubles). They felt zt the time, it did not neeed it, but all info indicates that CBR is close behind.